As far as Vacuum is concerned, I have a low vacuum cam. I run about 12-14" and I also have to wait for the booster to charge up, then it holds. Are you sure your booster isn't leaking? or Your Check valve is it working right? I have something on testing out brake boosters a friend sent me last year, I'll see if I can post it here.
Ragu, what's your engine size, compression ratio, cam specs and current initial timing?
